1 Introduction
The large-scale deployment of wireless communication services and advances in portable computers are quickly making ubiquitous computing into a reality. One class of applications that can benefit from this expanding and varied infrastructure is collaborative computing. Examples include computer-supported cooperative work, computer-based instruction, and mobile operator support in industrial installations. Given their synchronous and interactive nature, collaborative applications are particularly sensitive to heterogeneity among the computing devices and the network connections used by participants. Pavilion [1] is an object-oriented framework for developing collaborative Web-based applications. Pavilion provides a suite of proxy-based services and protocols that help to mitigate differences among networks and devices.